I think it's a bit of both!
Obviously their is a bit of marketing hype for selvedge denim - they want us to buy it. At the same time there is marketing hype for everything else! I don't see why it would be listening to all marketing to buy selvedge denim but not listening to buy normal denim - same thing!
People buy designer clothes for a few reasons, the look, the image of the brand, the quality/craftsmanship etc. With the selvedge you are buying into a more exclusive type of product (however I do think alot of the info put out about it being hard to make, they don't make machines to make selvedge denim anymore etc is a bit OTT. They have modern machines which can make selvedge denim now. Look at how many brands use selvedge denim). As with all things there is a big difference between the various selvegde denims available. You have Gap & Top Man selling jeans for £30 or so then you have the Sugar Canes, samurai,studio d'artisan, warehouse, pure blue etc which are selling for a few hundred £££s. Yes they may both be selvedge denim but their is a big difference! Topman will be chemical dyed, mass produced etc. Some of the other brands will be hand dyed using indigo, woven on a vintage loom giving a different texture & look to the cheaper selvedge, made using special types of cotton & threads etc.
A couple of pics of cotton being dyed ready for making into selvedge denim.
